Abstract: A single integrated circuit (12). The integrated circuit comprises a first circuit (14x) having a data path, the first circuit consisting of a first number of logic gates for performing a plurality of logic functions. The integrated circuit also comprises a circuit (22x) for indicating a potential speed capability of the data path. The circuit for indicating comprises a second number of logic gates (82, 92) for performing the plurality of logic functions, wherein the second number is less than the first number. The circuit for indicating also comprises additional circuitry (88, 98) for representing parasitic characteristics in the data path.

Abstract: A system for, and method of optimizing an operation of an oversampled filter bank and an oversampled discrete Fourier transform (DFT) filter bank designed by the system or the method. In one embodiment, the system includes: (1) a null space generator configured to produce a basis of a null space of a perfect reconstruction condition matrix based on a first window of the oversampled filter bank and (2) an optimizer associated with the basis generator and configured to employ the null space and an optimization criterion to construct a second window of the oversampled filter bank.

Abstract: A method is provided for automatically optimizing parameter selection in a communication system having one or more channels for transmitting and receiving signals by the steps of: receiving a signal from a channel; characterizing impairments in the channel while gathering statistics using the received signal; analyzing the impairments to obtain recommendations for parameter modifications for improved performance; and modifying the parameters based on the recommendations. Other systems and methods are disclosed.

Abstract: A communication device (116, 216, 316, 416) for a communications network having a first integrated circuit (IC) (141, 244, 344, 444) including one or more receivers (136, 236, 336) and a first MAC function (140, 240, 340), and a second IC (139, 242, 342, 442) including one or more transmitters (134, 234, 334) and a second MAC function (138, 238, 338). The first (141, 244, 344, 444) and second (139, 242, 342, 442) IC's are coupleable to a communications network for controlling the downstream and upstream communications, respectively.

Abstract: The methodology accomplishes adaptive hybrid selection during ADSL modem training. The adaptive hybrid selection method maximizes performance for ADSL modems in the presence of various impairments on the line by optimally selecting the appropriate hybrid based on line conditions. Specifically, the adaptive hybrid selection method is based on a measure directly coupled to the channel capacity.

Abstract: The invention teaches elimination of the need for allocating a telephony port or equivalent processor resource for realtime facsimile transmission through a broadband access gateway by replacing a fax modem or analog fax machine with a computer system having a network connection to the gateway. A software application on the computer uses a serial port redirector that provides a virtual communication port for facsimile software applications that would otherwise use a fax modem on a computer. The port redirector captures fax data sent to a serial communication port on the computer and sends it to the virtual fax module on the gateway. The gateway has a virtual fax software application associated which emulates a Class 1 or Class 2 fax modem interface from the client-side PC. The gateway uses a codec to convert fax data into ITU T.38 standards for “Procedures for real-time Group 3 facsimile communication over IP networks”. Packetized T.

Abstract: A method is disclosed for allocating processing resources, such as instruction execution which can be measured in MIPs or memory capacity, or other resources of a processor itself or resources used in the process of performing operations, such as memory resources, busses, drivers and the like, to functions in a queue waiting to be executed. This method includes the steps of determining the amount of processor resources available to be assigned, determining an estimate of the amount of resources needed for each function waiting in the queue to execute, and allocating the available resources to the functions using a hierarchical priority scheme. The hierarchical priority scheme assigns priority based on the environmental conditions, the achieved performance, and the amount of resource recently consumed by the function.

Abstract: Crosstalk can be cancelled in a composite communication signal (ym) which includes a primary signal component associated with communication data and which also includes a crosstalk signal component produced by applying a crosstalk coupling function to crosstalk data. An estimate (R, RCb(0), RCb(?f)AVG) of a statistical characteristic of the crosstalk signal component is obtained from the composite communication signal. A cancellation signal (26, 46) is generated based on the statistical characteristic estimate, and an estimate (29) of the communication data is produced based on the composite communication signal and the cancellation signal.

Abstract: A system and method for reordering tones of a DMT signal within a communication system is described. Cross tone correlated noise in a received signal is identified and rearranged such that tones with correlated noise are spread out throughout the received signal before being processed by a decoder such as, Viterbi decoder. In an embodiment, two tones with the most correlated noise are placed at each end of the sequence of tones presented to the Viterbi decoder. In some embodiment, the tones with correlated noise can be spread such that two adjacent tones with correlated noise have a minimum distance of at least three tones between them at the input to the Viterbi decoder. In other embodiment, tones in the received signal can be processed in various kinds of interleavers for reordering according to the interleaver scheme.

Abstract: An efficient framing scheme is described for the transmission of frame overhead data in next generation ADSL modems. As a result of this new framing scheme, the available data rate for the transmission of payload data increases. High payload data rates and consequently wider reach of the ADSL modem are the most important performance requirements and customer care-abouts for ADSL modems. This application explains the new framing scheme in detail and provides examples for the computation of the framing parameters.

Abstract: A method of correctly estimating the frequency offset when the CPE modem has already acquired and is tracking the OFDM burst boundaries in an OFDM-based, wireless communication system. CPS data in an OFDM-based, wireless communication system is modulated as QPSK data in the training tones of the data burst. As long as some bursts have the CPS data modulation and some bursts do not have the CPS data modulation, the CPS data can be recovered. A slip results when there is a linear phase difference across the tones (after the FFT) between the current and the previous burst. This linear phase difference is generally taken care of by the channel estimation obtained using the pilot tones. This phase difference is however, now compensated for correct frequency offset estimation which occurs before the channel estimation and CPS decoding steps.

Abstract: A circuit provides a reduced harmonic content output signal OUTA and/or OUTB that is modulated according to an input signal 231. The circuit has an oscillator circuit 210 and a harmonic rejection mixer (HRM) 230. The oscillator circuit 210 includes at least one “circuit portion” (FIG. 2A) configured to receive first and second orthogonal oscillator input signals (two of I, I?, Q, Q?) having respective first and second phases, and to provide an arbitrarily large number of oscillator output signals (?M) having respective mutually distinct phases that are interpolated between the first and second phases. Harmonic rejection mixer 230 is configured to use the input signal to modulate a combination of the oscillator output signals, the oscillator output signals being respectively weighted so as to provide an emulated sinusoidal signal constituting the reduced harmonic content output signal.

Abstract: A current-domain transmitter is configured to receive an input signal and provide a transmitted signal. The transmitter has a plurality of elements, operatively arranged between the input signal and the transmitted signal and configured to represent the input signal with respective electric currents whose respective current magnitudes are each substantially proportional to the input signal. The elements may include a current-steering digital-to-analog converter (DAC), a current mode filter (such as an LPF), a current mode mixer, and/or a current mode amplifier.

Abstract: The present invention provides for a method and apparatus for allocating data to subchannels used for ADSL transmission over a communication link which supports further system transmissions. An expected interference impact from the further system transmissions is estimated for the ADSL subchannels. Signal-to-noise ratios (SNRs) for the subchannels are determined for bit loading by an estimator (220). In one embodiment, actual noise associated with the communication link is used at initialization to determine a SNR which is subsequently modified by an adjusting unit (205) prior to bit loading responsive to the estimated interference impact. In another embodiment, a virtual noise signal, indicative of the estimated interference impact and generated by a noise signal generator (235), is summed with the actual noise prior to determining a SNR for bit loading.

Abstract: A method and apparatus permit a wireless communication device to be calibrated during manufacturing and subsequently re-calibrated while in use to correct for the effects of temperature changes on transmit power.

Abstract: A method of determining CPS data in an OFDM-based, wireless communication system resolves the phase angle difference between training tones in a burst without CPS data and training tones in a burst with CPS data and then demodulates the resulting difference phase angles to determine the CPS data. The method achieves timing correction/compensation in CPS decode operations associated with OFDM-based, wireless communication systems.

Abstract: A method of increasing the data rate in a wireless Ethernet employs clock switching between the preamble and the encoded data portion of a packet structure. A shift block includes a tail sequence and a head sequence that is inserted between the preamble and the encoded data portion. The clock switching occurs within the shift block between the tail and the head sequences. The tail sequence and the head sequence are each constrained to be a fixed sequence.

Abstract: Time domain equalizer determination for discrete multitone systems by tone error minimization from a starting point of a single-tone equalizer.

Abstract: A method of wirelessly communicating is disclosed. The method comprises generating a plurality of tones for a wideband orthogonal frequency division multiplex symbol (310), the tones including a plurality of contiguous zero-valued tones, inverse Fourier transforming the tones to a plurality of time-domain samples (312), copying a plurality of the time-domain samples as a portion of a cyclic block (314), the cyclic block (314) contiguous with the time-domain samples (312), time-domain window filtering the time-domain samples (312) and the cyclic block (314) to form a portion of the wideband orthogonal frequency division multiplex symbol (310), wherein the time-domain window filter (350) is a function ?(k) having the property that ?(k)+?(k+Nfft) is about equal to a constant ? where Nfft is the number of tones, and transmitting the wideband orthogonal frequency division multiplex symbol (310).

Abstract: A multiple access system for a network using multicarrier modulation. To contend for service a subscriber station selects an upcoming frame in whose contention window it will contend, selects a contention slot within the window, selects a contention channel corresponding to a subset of the carriers used by the network, and imposes a contention code differentially on the carriers in the contention channel.